Explanation:

• PASSEX (Passage Exercise) is a maritime exercise conducted between two or more navies which consist or navigation and communication drills as ships coordinate manoeuvres alongside each other.
• A passage exercise is normally undertaken whenever an opportunity arises, in contrast to pre-planned maritime drills.
• It increases operational readiness and interoperability among the naval forces.
• The Nimitz Carrier Strike Group of USA recently transited through Indian Ocean Region. During the passage, Indian Navy units undertook Passage Exercise (PASSEX) with US Navy.
• Indian Navy had also conducted similar PASSEXs with Japan and French Navy in recent past.

Hence only statements 1&2 are correct.